Roll back issue #948516 from Drupal 7 for now (which made down arrows in...

Roll back issue #948516 from Drupal 7 for now (which made down arrows in fieldsets part of the link) because it breaks RTL languages.

modules/system/system.theme.css

@@ -173,11 +173,11 @@ input.form-radio {
  *
  * @see collapse.js
  */
-html.js fieldset.collapsible .fieldset-legend a {
+html.js fieldset.collapsible .fieldset-legend {
   background: url(../../misc/menu-expanded.png) 5px 65% no-repeat; /* LTR */
   padding-left: 15px; /* LTR */
 }
-html.js fieldset.collapsed .fieldset-legend a {
+html.js fieldset.collapsed .fieldset-legend {
   background-image: url(../../misc/menu-collapsed.png); /* LTR */
   background-position: 5px 50%; /* LTR */
 }